Trestle.



A. W. GUTHAT.

, TRESTLE. APPLICATION FILED JUNE l2. I915- Patented July 18, 1916.

2 SHEETS-SHEET 1.

I 11' 15mm.

A. W. GUTHAT.

TRESTLE.

APPLICATION FILED JUNE 12. 1915.

2mm mm QZW Patented July 18, 1916.

2 SHEETS-SHEET 2- n for. t i. g;

TRES'ILE.

Specification of Letters Patent.

Patentedlluly 18, 1916.

Application filed June 12, 1915. Serial No. 33,781.

To all whom it may concern Be it known that I, ALBERT WV. GUTHAT, acitizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Trestles, of which the following is a specification.

This invention relates to trestles employed for supporting scaffolding,and its object is to provide a strong, safe and durable device of thiskind, and one which is simple in construction, and which may be easilytaken apart and adjusted.

The herein stated object is attained by means of a novel combination andarrangement of parts to be hereinafter described and claimed, referencebeing had to the accompanying drawing in which Figure 1 is a sideelevation of the trestle partly broken away; Fig. 2; is an end view ofthe same; Fig. 3 is a horizontal section on the line 3-3 of Fig. 1; Fig.4 is an elevation of the adjustable connection between the leg sectionsof the trestle; Fig. 5 is a sec tion on the line 55 of Fig. 4 and Fig. 6is a cross section on the line 66 of Fig. 5.

Referring specifically to the drawings, the trestle comprises ahorizontal beam or plank 5 supported by divergent legs 6, on which beamthe scaffold boards are supported in the usual manner. Two pairs of legsare provided, each pair having at its upper ends means for supportingthe beam 5, said ends being spaced sufficiently to accommodate the beam.These supporting means comprise plates 7 rigidly secured to the innerfaces of the legs by bolts 8, or other suitable fastenings, and areprovided with an outstanding horizontal bottom flange 9, forming a shelfon which the beam seats. Each leg carries one of these supportingdevices, the

supporting devices of the members of the respective pairs of legs beingopposite each other and cotiperating to support the adjacent end of thebeam. Beneath the shelf, the members of each pair of legs are connectedby a bolt 10 provided with a wing nut 11, these parts being provided tohold the legs against spreading. In order to prevent the beam frommoving in the direction of its length, that portion which is locatedbetween the legs has vertical grooves in its side faces in which seatvertical ribs 12 on the faces of the plates 7. On the ends of the plates7 are short flanges 13 which fit over the edges of the legs and thusassist to hold the plates in place on the legs.

The legs 6have a bottom section 14, an adjustable connection beingprovided in order that the trestle may be adjusted as to height. Thisconnection comprises the following parts: In the outer face of the legsection 6 is a longitudinal groove 15 in which slidably fits acorresponding rib 16 mounted on the contiguous inner face of the legsection 14, said rib having ratchet teeth 17. To the lower end of theleg section 6 is rigidly secured a yoke-shaped plate 18 which straddlesthe adjacent portion of the leg section 14. The side portions of theyoke have bearings 19 which support a link 20 which extends around bothleg sections, that portion of the yoke plate 18 which straddles the legsection 14 having a recess to accom modate the link. That portion of thelink which is opposite the inner face of the leg section 6 is spacedtherefrom and has, midway between its. ends, a tapped hole which takes athumb screw 21. In the leg section 6 is a recess 22 which opens throughthe inner face thereof and communicates with the groove 15. In thisgroove is pivotally mounted, on a transverse pin 23, a pawl or dog 24,which is designed to engage the ratchet teeth 17. From the back of thepawl extends a stem 25 having an enlargement 26 at its outer end andlocated opposite the inner end of the thumb screw 21. The pawl also hasa finger piece 27 which projects from the recess 22 and is designed toafford a means for releasing the pawl if it should be stuck to theratchet teeth.

To adjust the leg sections to the desired height, the thumb screw 21 isbacked until the pawl 24 is clear of the ratchet teeth 17, the pawldropping back by gravity, unless it should sti'ck,in which event it canbe disengaged bya rap on the finger piece 27. The leg sections are nowunlocked, and free to be adjusted relative to one another, and after thedesired adjustment is effected, the thumb screw is advanced to engagethe pawl with the ratchet teeth, whereupon the leg sections are securelylocked together in adjusted position. The mounting of the ratchet bar 16in the groove 15 effectually prevents a sidewise twist of the legsections, thereby preventing slippage of the pawl out of engagement withthe ratchet teeth. The

sections 6 of each pair of legs are provided With an angle iron spacingbar 28 from Which braces 29 extend to the beam 5.

I claim The combination of a pair of members having a slidableconnection to permit ad justment as to length, one of said membershaving a longitudinal ratchet bar and the other member having a recessopening to said ratchet bar, a pawl pivotally mounted in the recessandadapted to engage the ratchet bar, the rear end of the paWl proj ectingfrom the recess, a yoke carried by the last-mentioned member andstraddling the other member, a link carried by the yoke and passingaround both members, and a screw carried by the link and engageable withthe pawl for locking the same to the teeth of the ratchet bar.

In testimony whereof I afliX my signature in presence of tWo Witnesses.

ALBERT WV: GUTHAT. Vitnesses:

S. J. LEHRER, H. G. BATOHELOR.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

